anonymous

4 years ago

#1: Which of the following scientists came up with the first widely recognized atomic theory?
A. John Dalton
B. Antione Lavoisier
C. Robert Millikan
D. J.J. Thomson
***My answer: A. John Dalton
is that right??

#2: What do we now call the negative particles that Thomson said were parts of all atoms?
A. protons
B. neutrons
C. electrons
D. cathode rays
**Not quite sure... :( Either B or C but idk for sure which one :(

You got the first one, as for the second one, remember that
Protons are positively charged particle.
Neutrons, as the name implied, has no charge.
Electrons will be the opposite of protons, negatively charged.

oh and #3 really fast.. i think i got this one right :)
#3: Which of the following is Robert Millikan credited with discovering?
A. the charge-to-mass ratio of the electron
B. the charge of a neutron
C. the mass of an electron
D. the nucleus of the atom
***My answer: C. mass of an electron.. is that right???? :D

You're right for Number 2, as for Number 3 is about the Milikan oil drop experiment and the charge on an electron is negatively charged which causes rise and fall by changing the voltage across the plates.